Dietary protein restriction and selective preference for a protein-containing diet in the golden hamster...

Two experiments were performed to examine protein appetite in golden hamsters (Mesocricetus auratus). In Experiment 1, hamsters were maintained for 10 days on either a protein-free or a nutritionally complete maintenance diet, and they were also given access to protein-rich and carbohydrate-rich test diets for 6 h/day. Hamsters maintained on the protein-free diet strongly preferred the protein test diet, but hamsters on the complete diet showed no such preference even when their caloric intake was matched to that of hamsters on the protein-free diet. In Experiment 2, hamsters that had developed a preference for the protein test diet while maintained on the protein-free diet were given Purina Chow for 25 days to permit them to recover from their protein deficiency. When later maintained on the complete diet, these hamsters did not demonstrate a preference for the protein test diet when maintained on the complete diet, but did so when returned to the protein-free maintenance diet. These findings indicate that dietary protein restriction causes hamsters to develop a strong preference for a protein-rich diet and that this preference may be manifested only in response to a physiological need for protein.